Machines, such as power shovels and excavators, may include a deck or other platform that rotates above continuous tracks, wheels, pontoons, etc. Extending from the deck, the machine may further include a boom for an articulated arm or crane designed to operate a bucket, a breaker, a hook, or any other such work tool. Accordingly, such machines typically include one or more actuators designed to move the tracks, rotate the deck, and operate the articulated arm and work tool.
Above machines are designed to operate in substantially-repetitive work cycles. By way of example, a power shovel or excavator may typically operate in work cycles which may include digging, lifting, swinging, dumping, and returning steps for operating a bucket to dig and load fragmented rock, earth, minerals, overburden, and the like for mining purposes. Powering these operations are mechanical or electro-mechanical power systems designed for supplying power for a combined maximum power demand of the work tool and some auxiliary loads, including cooling loads etc. of the machine. Most of the time the machine underutilizes the available power due to non-uniform peak power demand based on repetitive nature of work cycles. Thus, the machine operates with an engine that is oversized for majority of its power demand profile. The oversized engine affects initial purchasing cost, operating and repairing costs, and overall life of the machine.
U.S. Pat. No. 8,606,451 (hereinafter referred to as '451 reference) describes an energy system for heavy equipment where the energy system changes the power output of the engine based upon a change in electrical demand. The '451 reference includes a method for providing electrical power to a bus for powering an actuator, providing electrical power to the bus from an energy storage device in response to an increased electrical demand on the bus, and increasing power output of the engine at a rate less than the maximum capability of the engine. However, the '451 reference does not disclose details about any solution for reduction in the engine size.
Therefore, an improved energy storage system for the machine is required.